With the continuous development of integrated circuits (ICs) manufacturing technology, the requirements on the integration level and the performance of the ICs have become increasingly high. In order to improve the degree of integration and reduce production cost, the critical dimension of electronic components is steadily reduced and the circuit density in the ICs continuously increases. Such development makes the wafer surface unable to provide enough area for the fabrication of interconnections.
Currently, to accommodate the requirements for fabricating interconnections as the critical dimensions become smaller, interconnection structures are usually used to connect different metal layers or connect a metal layer with a substrate. As the technology node advances, the dimension of interconnection structures also becomes smaller and smaller.
As the dimension of interconnection structures becomes smaller, the reliability of conventional interconnection structures needs to be improved. The disclosed interconnection structures and fabrication methods thereof are directed to solve one or more problems set forth above and other problems in the art.